There are unfortunately some subreddits which are still the best place to find timely info about certain topics - for example video game subs run by the developers of the game. Lemmit is a way to subscribe to those while not giving Reddit any more "engagement" or ad views.
The bot that runs Lemmit only posts on its own instance, so users like me only see it when we subscribe explicitly (or the All view I guess, but that's a mixed bag already. Edit: and each user could choose to ban it if they want)
It showing up on all was exactly the problem. It was spam and it made reading all a bad experience. Id be for unbanning the bot if there was a way to keep it off all.
If it only reposted a small amount from niche subs then that would be different, but it completely spams the whole of Lemmy with zero-effort content that no-one interacts with. Makes browsing 'all' unpleasant for everyone else, even if you don't like doing that yourself. And if you think one spam bot is acceptable, then where do you draw the line? Ten? A hundred? Should we make the effort to individually ban all of them ourselves?
I guess we just have different opinions on things like how much 'effort' it represents, how important it is that people interact, etc.
I feel like Lemmy will very soon be at the point where the All page isn't going to be useful to sort by New (if it's not there already) so minor cleanups like banning Lemmit aren't going to make much difference. Switch it to something like Hot and I'm sure it won't show up much at all, nor other "spam" bots.
If the bot was adding to the already taxing load on the lemmy.world server, how is it fair to those wanting to make this place anew rather than regurgitating reddit posts. In my (possibly unpopular) opinion, if you want to see stuff on reddit, find an alternative method that won't inconvenience others.
I can't speak for the admins, but my guess is that since only Lemmit communities that lemmy.world users subscribe to would be replicated here, it might not make much additional load. Also there isn't much voting or commenting on those posts.